Grinding machine



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J. N. HEALD ET AL -GRNDING MACHINE k3 Filed Jan. 9 Q23 4`heets-Sheet 5 N. HEAMB ma' GRINDING MACHIXJE l Patented ci. 19, 1926.

.UNITED STATES PATENT oFFicE.-

JAMES N. HEA'LD, ALDEN M. DRAKE, AND WALDO J. GUILD, OF WORCESTER, MASSA# CHUSETTS, ASSIGNOR T0 THE HEALD MACHINE Cf()llllPANY,l OF WORCESTER, MASSA- CHUSET'IS, A CORPORATON OF MASSACHUSETTS.

GRINDING MACHINE.

Application ined :rannarya 1923, serial No. 611,633.

The presentv invention relates to grinding machines, and in particular to the means employed in such a machine for imparting rotation to the work; the invention also relates to the means employed in such a machine `foriprocuring rotation of the grinding wheel and forI facilitating relative movement between said wheel and the rotating Work.

The invention resides in the several Yfeatures of novelty hereinafter described in detail and specied in the appended claims,

reference being had to the accompanying drawings, v

Fig. 1 is a view in .front elevation of a grinding machine embodying the invention. Fig. 2 is an end elevation of said machine, certain parts being shown in section. y Fig. 3 is a rear elevation of the oppos1te end of said machine. V Fig. t is an end view of the parts shown in Fig. 3. 4

Fig. 5 is afront elevation of -a machine embodying a modification of the invention. Fig. 6 is a fragmentary sectional view showing a detail of construction.

Like reference characters refer to like parts in the different figures.

Referring first to Figs. 1, 2, 3 and 4, the invention is shown as applied to an internal grinder, the base 1 of which provides the usual ways 2, 2 for the longitudinal travel of a table 3. The latter serves for the supully described in the aforesaid copending application. tion of these fluid pressure controlling and reversing mechanisms form no part of the present invention, it being suicient to note `that the automatic operation of the valve port, as hereinafter described, of a Spindle r 4L carrying a grinding wheel -5, said spindle being rotated at high speed during the back and forth movement of table 3 by means ot' suitable bclting actuatedfrom an elongated drum 6, whose length corresponds approxi- 4 vniately to the throw or travel oi the table 3.

The movement of table 3 is obtained in the present instance Vby a fluid pressure controlling and reversing mechanism, of the type, for instance, disclosed in the eopending application of Drake & Hubbell, Serial No. 528,118,.iled January 9, 1922. Inl accordance with the disclosure of said copending application, the table 3, in the present instance, is provided with adjustable stops or dogs 7, 7 which, by their alternate engagements with a rocker arm 8, procure, through a link 9, the oscillation of a valve dev1ce, not shown, the latter being also under the independent hand control of a lever 10, as

device, by alternate engagement of the stops or dogs 7 and 7 with the lever 8, procures the flow of pressure medium in. one direction or'the other against .a double acting piston, not shown, the latter being suitably connected to the table 3, while the lever 10 affords a means for interrupting or changing, when desired,` the above described automatic action, as obtained by the dogs, and also for procuring, when desired, an extended moveine'nty of the table 3 to remove the latter from the iniiuence of said dogs.

For the support and rotation of the piece of work 11, the machine provides a head 12, which is mounted for swinging movement on a cross slide 13, the latter being adjustable transversely on the usual bridge 14 which spans the ways 2, 2 and the table 3. The head 12 has suitably journaled therein a spindle 15, on the inner end of lwhich the usual means are provided for holding or The construction `and operachucking the work 11 in centered relation to the axis of said spindle. Provisionv is made for angular adjustment of the head 12 on its supporting cross slide 13 to dispose the rotating work at various angles `to the line of travel of the Wheel 5, whereby to 'facilitate the grinding of bevelled or tapering internal surfaces, and to this end the head swivels on an axis provided by a stud 16, as shown in Fig. 2. `Provision may also be made for the procurement of a quick lateral displacement of the work axis, when grinding internal surfaces of ditlerent diameters on the same piece of Work, the slide 13 being movable transversely of the bridge 14 by any suitable means, such for instance as a feed screw 17, operable by a hand wheel 18 from the front of the machine; another screw 19 equipped with suitable locking nuts 20, 20 may be employed, if desired, to retain the slide 13 in any desired position of adjustment. y

In respect of procuring the rotation of work spindle 15, the resent invention contemplates a self-contained machine wherein the head 12 itself provides and carries the spindle actuator, the latter being here shown as an adjustable speed electric motor 21, mounted vertical in the head, with its shaft 22, as shown in Fig. 2, carrying a worm 23 in mesh with a worm gear 24 on the spindle 15. In this way is eliminated at once all the disadvantages of a belt drive for the work, or any interference with or obstruction to the ability of the head 12 to swivel freely in either direction on the axis p'rovided by the stud 16, or to be shifted laterally in either direction by the feed screw 17, it being understood, of course, that the motor 21 has flexible connections 25 supplying current thereto from a suitable source.

According to the present invention, lthe drive for-the grinding Wheel may be likewise self-contained in the machine, and to this end the driving drum 6 on the lower rear side of the machine has a belt connection 26 to a pulley 27 on an overhanging countershaft 28, the latter being carried at the rear of the machine in overhanging relaA tion to the base 1 and the ways 2, 2A of table 3. The shaft 28 carries a second pulley 29, by which a belt connection 30 drives a pulley 31 on the wheel spindle 4. 'In the machine herein illustrated, provision is made for a cross feed of the grinding wheel 5 in a direction transverse to the line of movement of table 3, and to this end the wheel spindle 4 is journalled ina cross slide 32, the latter being adjustable in ways provided by a member 32 which is secured to the table 3 by means of bolts 33.

In the above described arrangement of mechanism, the necessity for the lateral shifting of both belts 26 and 30 requires that provision be made for compensating for the changes in lengths of said belts and also that the downward pull of belt 26 be counteracted, to prevent excessive pressure between the table 3 and its ways 2, 2. According to the present invention, excessive downward pull on the table 3 is eliminated by the provision of means adapted to transfer said pull or strain directly onto the solid base 1 of the machine. Said means, as here shown, takes the form of a guide rail 34, formed on the rear side of the machine and presenting` an elongated inclined face, corresponding in length to the drum 6, for the travel thereon of a roller 35. The latter is journaled in the lower end of-a follower member 36 which is secured by bolts 37, 37 to the rear edge of table 3. Said bolts 37, as shown in Fi 6, pass loosely and freely through bolt oles 38 in the follower member 36, to permit limited rocking movement of the latter, relative to table 3, by the yielding of washers or springs 39 placed under the heads lof said bolts; this eliminates any necessity for extreme accuracy in lining up the rail 34 with the ways 2, 2 in which the table 3 slides.

The follower member 36 supports `an upwardly extending yokeV member 40, the latter being pivotally attached to the follower member on an axis provided by studs 41. At its upper end the yoke 40 provides bearings 42 for the belt driven countershaft 28, and said yoke member is held against swinging downward about its pivot shaft 41 by a link connection 43 with the cross slide 32. The construction is such that the pressure of the follower member 36 on rail 34 is substantially in line with the pull exerted on countershaft 28 by its driving belt 26, thus relieving the traveling table 3 of any excessive pressure occasioned by the downward pull of belt 26, and eliminating any tendency of said table to tipfup, or to bind by excessive friction on its right hand slide way 2. The lateral changes of position to which'the axis of shaft 28 is subjected, by reason of the adjust-ment of cross slide 32, are compensated for by the pivotal connections 44 and 45 of link 43, and by the pivotal connection 41 of yoke 40, which pivotal connections permit the parts to adjust themselves automatically to the different positions-of the slide 32 without disturbing the essential pressure transmitting relations above set forth. Thedriving belt 26 is enabled to adjust itself to such changes of position, by the use of a tightener pulley 46, carried by a spring pressed arm 47, which is pivoted at 48 to the yoke 40, and the belt 30 is likewise held taut by a spring pressed tightener pulley 46.

ln Fig. 5 of the drawings is shown a modification of the arrangement adopted in Fig. 1, this modification involving the dis posal of a wheel head 50 on a cross slide 51, the latter being mounted on a bridge 52 whichspans the ways of the usual recipro-y cating table 3. The latter in the present instance, carries` the work supporting and rotating devices of the machine, here shownas consisting of a head 53 mounted for swinging movement on a cross slide 54, and equipped with the same motordriven work rotating devices as characterize the head 12 of Figs. 1 and 2. The cross slide 54 is adjustable transversely in ways 55, 55 provided by a plate 56 which is.se cured by bolts 57, 57 to the table 3', such adjustment being obtained by the use of a feed screw, not shown, operable by the usual hand wheel 58.

By the provision of a motor drive for the work, are eliminated at once all difficulties in belting to a movable headstock, and also any obstruction to the ability of the head 53 to swivel freely in either direction on its pivotal aXis, or to be shifted crosswise in either direction by the hand wheel 58; in addition, the flexible connections supplying current to the motor, allow the head to traverse back and forth with the table 3',

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under the action ot the previously described fluid pressure controlling and" reversing mechanism vassociated with said table. By this construction is avoided the neecssity for any special mechanism tor transmitting rotation to the grinding wheel 59; the shaft of the latter is supported inthe head 50, which is not subjected to longitudinal movement, and hence may be driven, for instance, by an ordinary belt connection toa pulley 60, from an ordinary narrow pulley, not shown, carried either on an overhead countershaft, or on a shaft in the base of the machine.

We claim,

l. lin a grinding machine, a. base, a travelling table supported on said base, a grinding wheel carried by said table, a pressure transmitting member attached to said table, but allowing said member a slight vertical movement relative to said' table, an extension on said base for supporting said member, and a belt drive for said wheel, beyond said pressure transmitting member, and exerting the downward pull which is taken.' said pressure transmitting member. 2. ln a grinding machine, a base, longitudinal ways provided thereby, a table travelling in said ways, a grinding wheel carried by said table, a belt drive for saidwheel exerting a4 downward pull in overhanding relation to the support aliforded by said ways,

and means loosely coupled to said table interposed between said belt drive and said ways for relieving said ways of the pressure resulting from said pull.

3. ln a grinding machine, a base, a table supported Aon said base for longitudinal movement, a grinding wheel ,carried by said table, a, multiple belt drive Jfor said wheel exerting a downward pull in overhanging relation tothe support aiiorded to said table, and a base extension for receiving the pressure resulting from said pullin all positions of said table, said base extension being inwardly disposed with reference to all courses of said belt drive so as. to receive the lresultant force of the tensions on said belts.

4l. lln a grinding machine, a base, a longitudinally travelling table supported by said base, a grinding wheel carried by said table, a pressure transmitting membertravelling with said table `and bearing on said base, and a belt drive for said wheel whose downward pull is taken by said pressure ltransmitting member, said belt drive having a driven member adapted to swing bodily about an axis provided by said pressure l.transmitting member, whereby to accommodate said belt drive to crosswise adjustment of said wheel on said. table.

-Dated this sixth day of January, 1923.

JAMES N. HEALD. ALBEN M. BRAKE. wALDo J. GUILD. 

